How Do Chimps Spell Relief? In Wilderness, It's L-e-a-f

August 18, 1985|By KNT News Service

What does a wild chimpanzee do for a bellyache? It rambles down to the neighborhood bush and swallows a medicinal leaf.

At least that appears to be the case in Tanzania, where scientists have seen chimps swallowing leaves that contain a potent antibiotic, the same natural medicine used by African tribe members and Canadian Indians.

It is the first time that animals have been seen apparently using plants as medicine, said Manuel Aregullin, a plant chemist at the University of Arizona who helped isolate the antibiotic.

''This is the first time the hypothesis has been raised that an animal is capable of, if you will, such an intelligent decision.''

The leaf-eating was first observed in the early 1970s by Richard Wrangham, now a professor of anthropology at the University of Michigan.

He was following a group of chimpanzees from dawn to dusk as part of a graduate study under primatologist Jane Goodall when he noticed something peculiar.

''Every now and again,'' he said, ''the chimps would leave their nests in the early morning, and instead of heading for the nearest available fruit tree, to my surprise they would head for little patches of this particular plant.''

The plant is Aspilia, a member of the sunflower family, with 6-foot stalks topped with small yellow flowers, Wrangham said.

A chimpanzee would carefully examine the rough-surfaced leaves and select one that was young and tender. It would stick the leaf in its mouth, roll it around for about 10 seconds, then swallow it whole. The leaves passed through the animal undigested.

Wrangham learned that species of Aspilia are used by about 30 African tribes to treat stomachaches, worms, superficial cuts and burns and eye infections.

But a number of years passed before chemists at the University of California at Irvine isolated and identified the active ingredient: a red oil called Thiarubrine A.

''This oil is one of the most potent bioactive chemicals ever discovered,'' Wrangham said. ''It kills just about anything it comes into contact with.''

Another scientist, G.H.N. Towers of the University of British Columbia, had in the meantime isolated the same oil from another plant in the sunflower family that was used medicinally by the Okanagan-Colville Indians of British Columbia and Washington.

The scientists, including chemist Eloy Rodriguez of the University of California at Irvine, described their findings this spring in the journal Experientia.

Laboratory tests indicate that the red oil kills a number of human disease organisms, including Staphylococcus and Streptococcus bacteria, nematode worms and fungi.

Wrangham plans a series of studies at the Yerkes Regional Primate Research Center in Georgia to find out if captive chimps will eat the leaves and if the leaves actually cure medical problems, such as worms.